Research / 2020 / Article / Fig 5

Research Article

Sharkskin-Inspired Magnetoactive Reconfigurable Acoustic Metamaterials

Figure 5

Magnetoactive reconfigurable acoustic diode. (a–d) Schematics, samples, and numerical simulations at 8650 Hz of four states: reference state (a), object state (b), cloak-like state (c), and blocked state (d). The object used is a cotton-covered plastic block. The selective actuation of two pillars in (d) is because of their higher iron volume fraction (18.48% by weight). (e) The acoustic transmission of four states in functions of the frequency. (f) The evolution of the transmitted acoustic pressure at the cloak-like and blocked states at 8650 Hz with cyclically switching magnetic fields. (g) Schematic of a diode. (h, i) Schematics and numerical simulations to show the acoustic wave propagation of the magnetically actuated (i.e., 0.13 T) acoustic diode in the forward (h) and backward (i) directions. (j) The experimentally measured acoustic transmissions of the acoustic diode in the forward and backward directions. (k) Schematic of a diode. (l, m) Schematics and numerical simulations to show the acoustic wave propagations of the acoustic conductor in the forward (l) and backward (m) directions. (n) The experimentally measured acoustic transmissions of the acoustic conductor in the forward and backward directions.